For many of the immigrant women working the fields and packing plants of America, the job comes with the low wages, gruelling physical work and exposure to harmful chemicals, but for some, it also comes with sexual harassment.

Exact numbers are hard to come by as rape is normally an underreported crime, but even more so when the population is undocumented women.

That's the subject of PBS's Frontline documentary "Rape in the Fields" produced in partnership with the Center for Investigative Reporting and Univision. The documentary airs tonight on PBS and on Saturday June 29th on Univision in Spanish.

In the yearlong investigation, documentary producers spoke to dozens of women from tomato fields in Florida to packing plants in Iowa who say they've been sexually abused on the job.

In this video, Lowell Bergman, the documentary's co-producer, writer and correspondent spoke to Univision News's Jorge Ramos about how the documentary came about.